During the 1910s and 1920s education in the US was something that the American businesses rallied for. They wanted the government to encourage education, especially the high schools as all the skilled labor required for business came from the education system in the country run by the goverment.

But the Great Depression in the 1930s changed the outlook completely. Businesses no longer needed more skilled people and instead were opposed to the government funding education as it required resources that were collected as taxes from the businesses. Businesses instead wanted tax breaks and were intent on reducing the money that went towards education.

Schools were intended to be only for the elite as they would run the businesses and the labor had no need for skills that they gained at school. This led to the shutdown of schools on a large scale, especially those for the non-whites as education was no longer considered important for the work they were to do.

In the early 20's there was a record number of schools. It was the era of the one room school house. Towards the end of the decade consolidation was the norm and many of the one room school houses were replaced with larger consolidated schools.

Something that might be considered as well is when schools became bigger, sometimes their focus changed. With increased industrialization of America, the purpose of many schools became to produce students who were cabable and skilled to become factory workers. The schools were business and educating competent workers was the product.

I have read some interesting research on education in the twenties and thirties. Basically, more schools were built during the prosperity of the twenties. Educational movements were progressive and experimental. There was Dewey to conend with. He felt that children should experience their educational. During the thirties, times were tough. Those beautiful grand schools were mostly empty, and people were so desperate for jobs that there were higher quality teachers. Or so I have read.